US20050156957A1

Movatterモバイル変換

Info

Publication number: US20050156957A1
Application number: US10/760,265
Authority: US
Inventors: Kia Silverbrook; Tobin King
Original assignee: Silverbrook Research Pty Ltd
Current assignee: Silverbrook Research Pty Ltd
Priority date: 2004-01-21
Filing date: 2004-01-21
Publication date: 2005-07-21

Abstract

A method of operating a photofinishing business and which comprises utilizing a digital photofinishing system that incorporates a digital processor, a printer and means for feeding print media to the printer from a roll of the print media; the digital processor being provided with digitised data from a source that is provided by a customer, and which is representative of a photographic image, and the data being processed in a manner to generate a printer drive signal that is representative of the photographic image, the printer being coupled to the digital processor and the drive signal being processed to effect page-width printing of the photographic image on the print media as it is fed directly to the printer from the roll, and the printed image being furnished to the customer who is charged for the printing service.

Description

FIELD OF THE INVENTION

This invention relates to a method of operating a digital photofinishing business and to a franchising operation that embodies that business. One aspect of the method involves a photofinishing system that provides for page-width printing of print media that is fed directly from a roll of the media to a print head assembly.

CROSS-REFERENCE TO CO-PENDING APPLICATIONS

The following applications have been filed by the Applicant simultaneously with the present application:



WAL01US	WAL02US	WAL03US
WAL04US	WAL05US	WAL06US
WAL07US	WAL08US	WAL09US
WAL10US	WAL11US	WAL12US
WAL13US	WAL14US	WAL15US
WAL16US	WAL17US	WAL18US
WAL19US	WAL20US	MPA01US
MPA02US	MPA03US	MPA04US
MPA05US	MPA06US	MPA07US
MPA08US	MPA09US	MPA10US
MPA11US	MPA12US	MPA13US
MPA14US	MPA15US	MPA16US
MPA17US	MPA18US	MPA19US
MPA20US	MPA21US	MPA22US
MPA23US	MPA24US	MPA25US
MPA26US	MPA27US	MPA28US
MPA29US	MPA30US	MPA31US
MPA32US	MPA33US	RRA01US
RRA02US	RRA03US	RRA04US
RRA05US	RRA06US	RRA07US
RRA08US	RRA09US	RRA10US
RRA11US	RRA12US	RRA13US
RRA14US	RRA15US	RRA16US
RRA17US	RRA18US	RRA19US
RRA20US	RRA21US	RRA22US
RRA23US	RRA24US	RRA25US
RRA26US	RRA27US	RRA28US
RRA29US	RRA30US	RRA31US
RRA32US	RRA33US	SMA01US
SMA02US	SMA03US	SMA04US
SMA05US	SMA06US	SMA07US
SMA08US	SMA9US

The disclosures of these co-pending applications are incorporated herein by reference. The above applications have been identified by their filing docket number, which will be substituted with the corresponding application number, once assigned.

BACKGROUND OF THE INVENTION

Digital photofinishing systems are known and employ a variety of technologies, including laser exposure of photographic film, dye sublimation and inkjet printing using conventional types of printers. The present invention has been developed to provide for page-width printing of print media that is fed directly from a roll of the media to a print head assembly so as to facilitate application of the invention to photographic processing in the context of so-called Minilab photographic services.

SUMMARY OF THE INVENTION

According to one of its aspects the present invention provides a method of operating a photofinishing business and which comprises utilizing a digital photofinishing system that incorporates a digital processor, a printer and means for feeding print media to the printer from a roll of the print media. The digital processor is provided with digitised data from a source that is provided by a customer, and which is representative of a photographic image, and processes the data in a manner to generate a printer drive signal that is representative of the photographic image. The printer is coupled to the digital processor and processes the drive signal to effect page-width printing of the photographic image on the print media as it is fed directly to the printer from the roll. The printed image is furnished to the customer who is charged for the printing service.

The roll of print media is advantageously provided by way of a replaceable cartridge, which may also be employed to carry at least one reservoir of ink for the printer.

In accordance with another of its aspects, the invention provides a method of operating a photofinishing franchise in which a franchisee is provided with:

a) a digital photofinishing system as above defined, and
b) as and when required by the franchisee, cartridges containing a roll of the printing media and printing fluid to be used in printing images on the print media, and wherein a fee related to utilization of the photofinishing system is charged to the franchisee.

The invention will be more fully understood from the following description of an embodiment of a digital photofinishing system that is employed in operation of the business and the franchise methods. The description is provided with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a schematic representation of the digital photofinishing system,

FIG. 2 shows in perspective cabinetry that mounts and contains components of the digital photofinishing system,

FIG. 3 shows cabinetry that is similar to that ofFIG. 2 but which also incorporates a conventional film processing system,

FIG. 4 shows an exploded perspective view of the cabinetry ofFIG. 1 and components of the digital photofinishing system,

FIGS. 5 and 6 show right hand and left hand perspective views respectively of the components of the digital photofinishing system removed from the cabinetry ofFIG. 1,

FIG. 7 shows an exploded perspective view of the components ofFIGS. 5 and 6 together with ancillary components,

FIG. 8 shows a sectional elevation view of the components ofFIGS. 5 and 6,

FIG. 9 shows a perspective view of two (upper and lower) confronting print head assemblies that constitute components of the digital photofinishing system,

FIG. 10 shows an exploded perspective view of the print head assemblies ofFIG. 9,

FIG. 11 shows a sectional end view of one print head assembly of a type that is slightly different in construction from that shown inFIGS. 9 and 10,

FIG. 12 shows a perspective view of an end portion of a channelled support member removed from the print head assembly ofFIG. 11 and fluid delivery lines connected to the support member,

FIG. 13 shows an end view of connections made between the fluid delivery lines and the channelled support member ofFIG. 12,

FIG. 14 shows a printed circuit board, with electronic components mounted to the board, when removed from a casing portion of the print head assembly ofFIG. 11,

FIGS. 15 and 16 show right hand and left hand views respectively of a cartridge that constitutes a removable/replaceable component of the digital photofinishing system,

FIG. 17 shows an exploded perspective view of the cartridge as shown inFIGS. 15 and 16,

FIG. 18 shows, in perspective, a sectional view of a portion a print head chip that incorporates printing fluid delivery nozzles and, in the form of an integrated circuit, nozzle actuators,

FIG. 19 shows a vertical section of a single nozzle in a quiescent state,

FIG. 20 shows a vertical section of a single nozzle in an initial activation state,

FIG. 21 shows a vertical section of a single nozzle in a later activation state,

FIG. 22 shows a perspective view of a single nozzle in the activation state shown inFIG. 21,

FIG. 23 shows in perspective a sectioned view of the nozzle ofFIG. 22,

FIG. 24 shows a sectional elevation view of the nozzle ofFIG. 22,

FIG. 25 shows in perspective a partial sectional view of the nozzle ofFIG. 20,

FIG. 26 shows a plan view of the nozzle ofFIG. 19,

FIG. 27 shows a view similar toFIG. 26 but with lever arm and moveable nozzle portions omitted,

FIG. 28 illustrates data flow and functions performed by a print engine controller (“PEC”) that forms one of the circuit components shown inFIG. 14,

FIG. 29 illustrates the PEC ofFIG. 28 in the context of an overall printing system architecture, and

FIG. 30 illustrates the architecture of the PEC ofFIG. 29.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT

As illustrated schematically inFIG. 1, the digital photofinishing system (referred to hereinafter as a “photofinishing system”) comprises acomputer20 which is arranged selectively to receive an input from an input source21 which, although not specifically illustrated inFIG. 1, might typically comprise one or more of:

a) A scanning device.
b) A dedicated photo (film or print) scanning device.
c) A computer disk.
d) A digital camera output.
e) A digital camera memory card.
f) A digital file stored on a photographic negative or print.
g) An internet (or intranet) connection.

A control and/ormonitoring device22 is connected to the computer for effecting control and/or monitoring functions and, although not specifically illustrated, such device might typically comprise one or more of:

a) A keyboard.
b) A touch screen, as illustrated inFIGS. 2 and 3.
c) A mouse.
d) A monitor.

Digital output signals23 from the computer might be directed or routed to one or more of a variety of devices such as:

a) A data storage device.
b) A file storage device or system.
c) An internet connection.
d) One ormore printers24 as shown inter alia inFIG. 1.

Aprint media supply25, aprinting fluid supply26 and anair supply27 are coupled to the (or each)printer24, and printed media from the printer(s)24 is directed to astorage device28 by way of a drier29 and aslitting device30.

The photofinishing system as illustrated inFIG. 1 may comprise and be termed a “digital minilab” for processing and printing photographic images that are fed to thecomputer20, either directly or indirectly, as digitised images from input sources such as those referred to previously. In such case theprint media supply25 might comprise paper, card or plastic foil, all in either sheet or roll form, and the printing fluid supply might comprise one or more printing inks, depending upon whether the printer(s) is (or are) driven to produce colour prints, black-on-white prints or “invisible” infrared digital image encoded prints. Also, when processing and printing photographic images, the slittingdevice30 may be driven to cut differently sized prints from a single width roll of print media. Thus, assuming a 12 inch (˜30 mm) wide roll of print media, the media may, for example, be slit to produce photographic prints having sizes selected from:

1-12×8 print
1-12×4 print
2-6×4 prints
3-4×6 prints
4-3×5 prints.

An important feature of the photofinishing system is that it employs what might be termed plain paper, page-width printing of photographic images. Thus, unlike conventional types of photographic minilabs that require: the development of film, the use of sensitised (coated) printing papers, specialised chemicals for use in developing, printing, stopping and fixing images, and skilled manipulation of developing/printing processes; the photofinishing system as described herein effectively embodies a computer controlled printing system which, at least in some embodiments, provides for relatively simple, high speed yet flexible digital processing and subsequent page-width printing of photographic images.

The photofinishing system may be integrated in the cabinetry shown inFIGS. 2 and 4 and, in that form, comprise acabinet31 having

doors

32,33 and34. The cabinet is itself provided internally with anupper shelf35 for receivingcomponents36 of the processing system, which are referred to later in greater detail, and withlower shelves37 for receiving replacement and/or expendedcartridge components38 which also are referred to later in further detail. Mounted to an upper deck of the cabinet are input signal-generating devices in the form of aflatbed scanner39, ahigh resolution 35 mm film and/orAPS cartridge scanner40, a touch screen control/monitoring device41 incorporating a liquid crystal display, and a USB input and/oroutput device42.

Print receiving trays

43 are located at one end of the cabinet and are coupled to atray elevating device44 of a conventional form.

The photofinishing system may alternatively be integrated in the cabinetry shown inFIG. 3 and, when in that form, further include afilm processing unit45. Thefilm processing unit45, although not illustrated in detail, comprises film processing apparatus of a conventional form which is known in the so-called minilab art for chemically developing and printing exposed photographic print and/or slide (transparency) film. Also, although again not shown, thefilm processing unit45 includes compartments and/or reservoirs as known in the art for receiving chemicals that conventionally are used in developing, stopping and fixing development and printing of film and print paper.

Thecomponents36 of the photofinishing system are now described in greater detail by reference toFIG. 1 and, selectively, to FIGS.4 to25 of the drawings.

Inputs to thecomputer20 are provided as standardised image compression signals and are processed, typically as JPEG files, using processing procedures that are known in the art. File manipulation, again using procedures that are known in the art, may be provided for in two ways:

1) Automatically, for example, for effecting artefact adjustments such as red-eye removal, colour density adjustment and histogram equalisation, and
2) Manually, for example, for effecting such image modifications as colour-to-black-and-white translation, sepia finishing, image rotation and image cropping.

The illustrated output23 (which in practice will be constituted by a plurality of output components) from thecomputer20 is directed to theprinter24 which, when in the form illustrated inFIGS. 9 and 10 comprises two confronting

print head assemblies

50 and51. The print head assemblies are arranged selectively to direct printing ink onto one or the other or both of two faces of a single sheet of print media or, as in the case of the illustrated photofinishing system, onto one or the other or both of two faces of print media from aroll75 of print media.

The

print head assemblies

50 and51 are mounted in space-apart relationship, that is they are separated by a distance sufficient to permit the passage of the print media between the assemblies during a printing activity, and the print head assemblies are mounted upon asupport platform52.

Each of the

print head assemblies

In general terms, and as illustrated in FIGS.9 to14 for exemplification purposes, each of the

print head assemblies

50 and51 comprises fourprint head modules55, each of which in turn comprises a unitary arrangement of:

a) a plasticsmaterial support member56,
b) four print head micro-electro-mechanical system (MEMS) integrated circuit chips57 (referred to herein simply as “print head chips”),
c) a fluid distribution arrangement58 mounting each of the print head chips57 to thesupport member56, and
d) a flexible printedcircuit connector59 for connecting electrical power and signals to each of the print head chips57.

Each of the chips (as described in more detail later) has up to 7680 nozzles formed therein for delivering printing fluid onto the surface of the print media and, possibly, a further 640 nozzles for delivering pressurised air or other gas toward the print media.

The fourprint head modules55 are removably located in achannel portion60 of acasing61 by way of thesupport member56 and the casing containselectrical circuitry62 mounted on four printed circuit boards63 (one for each print head module55) for controlling delivery of computer regulated power and drive signals by way offlexible PCB connectors63ato the print head chips57. As illustrated inFIGS. 9 and 10, electrical power and print activating signals are delivered to one end of the two

print head assemblies

50 and51 by way ofconductors64, and printing ink and air are delivered to the other end of the two print head assemblies by fluid delivery lines65.

The printedcircuit boards63 are carried byplastics material mouldings66 which are located within thecasing61 and the mouldings also carrybusbars67 which in turn carry current for powering the print head chips57 and the electrical circuitry. Acover68 normally closes thecasing61 and, when closed, the cover acts against aloading element69 that functions to urge the flexible printedcircuit connector59 against thebusbars67.

The fourprint head modules55 may incorporate fourconjoined support members56 or, alternatively, asingle support member56 may be provided to extend along the full length of each

print head assembly

50 and51 and be shared by all four print head modules. That is, asingle support member56 may carry all sixteen print head chips57.

As shown inFIGS. 11 and 12, thesupport member56 comprises an extrusion that is formed with seven longitudinally extendingclosed channels70, and the support member is provided in its upper surface withgroups71 of millimetric sized holes. Each group comprises sevenseparate holes72 which extend into respective ones of thechannels70 and each group of holes is associated with one of the print head chips57. Also, theholes72 of each group are positioned obliquely across thesupport member56 in the longitudinal direction of the support member.

Acoupling device73 is provided for coupling fluid into the sevenchannels70 from respective ones of the fluid delivery lines65.

The fluid distribution arrangements58 are provided for channelling fluid (printing ink and air) from eachgroup71 of holes to an associated one of the print head chips57. Printing fluids from six of the sevenchannel70 are delivered to twelve rows of nozzles on each print head chip57 (ie, one fluid to two rows) and the millimetric-to-micrometric distribution of the fluids is effected by way of the fluid distribution arrangements58. For a more detailed description of one arrangement for achieving this process reference may be made to the co-pending US Patent Application referred to previously.

An illustrative embodiment of oneprint head chip57 is described in more detail, with reference to FIGS.18 to27, toward the end of this drawing-related description; as is an illustrative embodiment of a print engine controller for the

print head assemblies

50 and51. The print engine controller is later described with reference to FIGS.28 to30.

A print media guide74 is mounted to each of the

print head assemblies

50 and51 and is shaped and arranged to guide the print media past the printing surface, as defined collectively by the print head chips57, in a manner to preclude the print media from contacting the nozzles of the print head chips.

As indicated previously, the fluids to be delivered to the

print head assemblies

50 and51 will be determined by the functionality of the processing system. However, as illustrated, provision is made for delivering six printing fluids and air to the print head chips57 by way of the sevenchannels70 in thesupport member56. The six printing fluids may comprise:

Cyan printing ink
Magenta printing ink
Yellow printing ink
Black printing ink
Infrared ink
Fixative.

The filtered air will in use be delivered at a pressure slightly above atmospheric from a pressurised source (not shown) that is integrated in the processing system.

The print media may, as indicated previously, be provided in various forms. However, as shown inFIGS. 8 and 17 the print media is conveniently provided in the form of apaper roll75 from which paper is, on demand, unrolled and transported through the printing, drying and slitting stages under the control of thecomputer20.

As illustrated, thepaper roll75 is housed in and provided by way of a replaceable/rechargeable,primary cartridge76, and the printing fluids are provided in refillable,secondary cartridges77 which are removably located within atubular core78 of theprimary cartridge76. Four only of thesecondary cartridges77 are shown inFIG. 17 of the drawings, for containing the four printing inks referred to above, but it will be understood that further secondary cartridges may be provided in the same way for infrared ink and for fixative if required.

Fluid outlet ports

79 are provided in anend cap80 that is located in anend wall81 of theprimary cartridge76 to facilitate connection of thefluid delivery lines65 to respective ones of thesecondary cartridges77.

Theprimary cartridge76 comprises a generallycylindrical housing portion82, that is shaped and dimensioned to surround a full roll of thepaper75, and a generally oblongpaper delivery portion83 that extends forwardly from a lower region of thehousing portion82. Both thehousing portion82 and thepaper delivery portion83 extend between

end walls

81 and84 of theprimary cartridge76, and the end walls are provided withbearings85 which carry thetubular core78. Low frictionroll support bearings86 are carried by thetubular core78 for supporting thepaper roll75, and anend cap87 having a bayonet fitting is provided for capping the end of the tubular core that is remote from theend cap80.

Thehousing portion82 of theprimary cartridge76 and the

end walls

81 and84 are, as illustrated, configured and interconnected in a manner to facilitate convenient removal and replacement of a spentroll75 and emptysecondary cartridges77. To this end, a latchingclosure88 is removably fitted to the end of the cartridge through which replacement paper rolls75 are loaded.

A slidingdoor89 is provided in a vertical wall portion of thehousing portion82 immediately above thepaper delivery portion83. Thedoor89 is normally biased toward a closed position by aspring90 and the door is opened only when the cartridge is located in an operating position (to be further described) and drive is to be imparted to thepaper roll75.

Located within and extending along the length of thepaper delivery portion83 of theprimary cartridge76 are a gravity loaded or, if required, a spring loadedtensioning roller91, adrive roller92 which is fitted with acoupling93 and apinch roller94. A slottedgate95 is located in the forward face of thepaper delivery portion83 through which paper from theroll75 is in use directed by the drive and pinch rollers.

The completeprimary cartridge76 is fitted as a replaceable unit into acompartment96 of a mountingplatform97 that supports, inter alia, the

print head assemblies

50 and51, the drier29 and theslitting device30. Thecartridge housing portion82 and thecompartment96 are sized and arranged to provide a neat sliding fit for the cartridge and to preclude significant relative movement of the components.

A paperfeed drive mechanism98 is mounted to thecompartment96 and comprises apivotable carrier99 that is pivotally mounted to anupper wall portion100 of thecompartment96 by way of apivot axis101. Afirst drive motor102 is also mounted to thecompartment96 and is coupled to thecarrier99 by way of adrive shaft103. Drive is imparted to theshaft103 by way of a worm wheel andpinion drive arrangement104, and pivotal drive is imparted to thepivotable carrier99 byshaft pinions105 that mesh withracks106 that are formed integrally withside members107 of the pivotable carrier.

Asecond drive motor108 is mounted to thepivotable carrier99 and is provided for imparting drive to aprimary drive roller109 by way of adrive belt110.

In operation of the photofinishing system, when the slidingdoor89 is opened, thefirst drive motor102 is energised to pivot thecarrier99 such that theprimary drive roller109 is moved into driving engagement with thepaper roll75, and thesecond drive motor108 is then energised to cause rotary drive to be imparted to thepaper roll75.

Athird drive motor111, which couples with thedrive roller92 by way of thecoupling93, is also energised in synchronism with the first and second drive motors for directing thepaper75 from thecartridge76 as it is unwound from theroll75. Feedback sensors (not shown) are provided as components ofelectric control circuitry112 for the

motors

102,108 and111.

Themotor control circuitry112 is mounted to the mountingplatform97 adjacent components of thecomputer20. As illustrated inFIG. 7, those components include apower supply113, aCPU114, ahard disk drive115 and PCI boards116.

Theprint head assemblies50 and51 (as previously described) are mounted to the mountingplatform97 immediately ahead of the slottedgate97 of the cartridge76 (in the direction of paper feed) and are selectively driven to deliver printing fluid to one or the other or both faces of the paper as it passes between the print head assemblies. Then, having passed between the print head assemblies the paper is guided into and through the drier29.

The drier29 comprises a series ofguide rollers120 that extend between side walls of ahousing121, and upper andlower blowers122 are provided for directing drying air onto one or the other or both faces of the paper as it passes through the drier.

The slittingdevice30 comprisesguide rollers123 and guidevanes124 that extend betweenside walls125 of the slitting device for transporting the paper through the slitting device following its passage through the drier29. Also, spaced-apartslitting blades126 are mounted toshafts127 which are, in turn, mounted to arotatable turret128, and the turret is selectively positionable, relative to a supportingroller128ato effect one or another of a number of possible slitting operations as previously described.

Aguillotine129 is also mounted to theslitting device30 and is selectively actuatable in conjunction with the slitting device to cut thepaper75 at selected intervals.

In operation of the above described and illustrated processing system, an input signal that is representative of a digitised photograph or photograph-type image is input to thecomputer20 and processed and, if required, manipulated for the purpose of generating an output signal. The output signal is representative of a photographic image to be printed by theprinter24 and is employed to drive theprinter24 by way of the printhead control circuitry62 in the

print head assemblies

50 and51. As indicated previously, the print head assemblies are driven to provide on demand page-width printing and relevant (typical) printing characteristics are identified as follows:

Pagewidth dimension—150 mm to 1250 mm
Print head width—160 mm to 1280 mm
Number of print head chips per print head—8 to 64
Number of nozzles per print head chip—7680
Number of nozzles per colour per print head chip—1280
Nozzle activation (repetition) rate—20 to 50 kHz
Drop size per nozzle—1.5 to 5.0 picolitre
Paper feed rate—Up to 2.0 m per sec

One of the print head chips57 is now described in more detail with reference to FIGS.18 to27.

As indicated above, eachprint head chip57 is provided with 7680 printingfluid delivery nozzles150. The nozzles are arrayed in twelve rows151, each having 640 nozzles, with an inter-nozzle spacing X of 32 microns, and adjacent rows are staggered by a distance equal to one-half of the inter-nozzle spacing so that a nozzle in one row is positioned mid-way between two nozzles in adjacent rows. Also, there is an inter-nozzle spacing Y of 80 microns between adjacent rows of nozzles.

Two adjacent rows of thenozzles150 are fed from a common supply of printing fluid. This, with the staggered arrangement, allows for closer spacing of ink dots during printing than would be possible with a single row of nozzles and also allows for a level of redundancy that accommodates nozzle failure.

The print head chips57 are manufactured using an integrated circuit fabrication technique and, as previously indicated, embody a micro-electromechanical system (MEMS).

Eachprint head chip57 includes asilicon wafer substrate152 and a 0.42 micron 1 P4M 12 volt CMOS microprocessing circuit is formed on the wafer. Thus, asilicon dioxide layer153 is deposited on thesubstrate152 as a dielectric layer and aluminium electrode contact layers154 are deposited on thesilicon dioxide layer153. Both thesubstrate152 and thelayer153 are etched to define anink channel155, and analuminium diffusion barrier156 is positioned about theink channel155.

Apassivation layer157 of silicon nitride is deposited over the aluminium contact layers154 and thelayer153. Portions of thepassivation layer157 that are positioned over the contact layers154 haveopenings158 therein to provide access to the contact layers.

Eachnozzle150 includes a nozzle chamber159 which is defined by anozzle wall160, anozzle roof161 and a radiallyinner nozzle rim162. Theink channel155 is in fluid communication with the chamber159.

Amoveable rim163, that includes amovable seal lip164, is located at the lower end of thenozzle wall160. Anencircling wall165 surrounds the nozzle and provides astationery seal lip166 that, when thenozzle150 is at rest as shown inFIG. 19, is adjacent themoveable rim163. Afluidic seal167 is formed due to the surface tension of ink trapped between thestationery seal166 and themoveable seal lip164. This prevents leakage of ink from the chamber whilst providing a low resistance coupling between theencircling wall165 and anozzle wall160.

Thenozzle wall160 forms part of lever arrangement that is mounted to acarrier168 having a generally U-shaped profile with a base169 attached to thelayer157. The lever arrangement also includes alever arm170 that extends from the nozzle wall and incorporates alateral stiffening beam171. Thelever arm170 is attached to as pair ofpassive beams172 that are formed from titanium nitride and are positioned at each side of the nozzle as best seen inFIGS. 22 and 25. The other ends of thepassive beams172 are attached to thecarriers168.

Thelever arm170 is also attached to anactuator beam173, which is formed from TiN. This attachment to the actuator beam is made at a point a small but critical distance higher than the attachments to thepassive beam172.

As can best be seen fromFIGS. 22 and 25, theactuator beam173 is substantially U-shaped in plan, defining a current path between anelectrode174 and anopposite electrode175. Each of the

electrodes

174 and175 is electrically connected to a respective point in thecontact layer154. Theactuator beam173 is also mechanically secured to ananchor176, and theanchor176 is configured to constrain motion of theactuator beam173 to the left of FIGS.19 to21 when the nozzle arrangement is activated.

The actuator beam807 is conductive, being composed of TiN, but has a sufficiently high enough electrical resistance to generate self-heating when a current is passed between the

electrodes

174 and175. No current flows through thepassive beams172, so they do experience thermal expansion.

In operation, the nozzle is filled with ink177 that defines ameniscus178 under the influence of surface tension. The ink is retained in the chamber159 by the meniscus, and will not generally leak out in the absence of some other physical influence.

To fire ink from the nozzle, a current is passed between the

contacts

174 and175, passing through theactuator beam173. The self-heating of thebeam173 causes the beam to expand, and theactuator beam173 is dimensioned and shaped so that the beam expands predominantly in a horizontal direction with respect to FIGS.19 to21. The expansion is constrained to the left by theanchor176, so the end of theactuator beam173 adjacent thelever arm170 is impelled to the right.

The relative horizontal inflexibility of thepassive beams172 prevents them from allowing much horizontal movement of thelever arm170. However, the relative displacement of the attachment points of the passive beams and actuator beam respectively to the lever arm causes a twisting movement that, in turn, causes thelever arm170 to move generally downwardly with a pivoting or hinging motion. However, the absence of a true pivot point means that rotation is about a pivot region defined by bending of the passive beams172.

The downward movement (and slight rotation) of thelever arm170 is amplified by the distance of thenozzle wall160 from the passive beams172. The downward movement of the nozzle walls and roof causes a pressure increase within the chamber159, causing themeniscus178 to bulge as shown inFIG. 20, although the surface tension of the ink causes the fluid seal11 to be stretched by this motion without allowing ink to leak out.

As shown inFIG. 21, at the appropriate time the drive current is stopped and theactuator beam173 quickly cools and contracts. The contraction causes the lever arm to commence its return to the quiescent position, which in turn causes a reduction in pressure in the chamber159. The interplay of the momentum of the bulging ink and its inherent surface tension, and the negative pressure caused by the upward movement of the nozzle chamber159 causes thinning, and ultimately snapping, of the bulgingmeniscus178 to define anink drop179 that continues upwards until it contacts passingprint media75.

Immediately after thedrop179 detaches, themeniscus178 forms the concave shape shown inFIG. 21. Surface tension causes the pressure in the chamber159 to remain relatively low until ink has been sucked upwards through theinlet155, which returns the nozzle arrangement and the ink to the quiescent situation shown inFIG. 19.

As can best be seen fromFIG. 22, theprint head chip57 also incorporates a test mechanism that can be used both post-manufacture and periodically after the prin head assembly has been installed. The test mechanism includes a pair ofcontacts180 that are connected to test circuitry (not shown). Abridging contact181 is provided on afinger182 that extends from thelever arm170. Because thebridging contact181 is on the opposite side of thepassive beams172, actuation of the nozzle causes thebridging contact181 to move upwardly, into contact with thecontacts180. Test circuitry can be used to confirm that actuation causes this closing of the circuit formed by the

contacts

180 and181. If the circuit is closed appropriately, it can generally be assumed that the nozzle is operative.

As stated previously the integrated circuits of the print head chips57 are controlled by the print engine controller (PEC) integrated circuits of thedrive electronics62. One or more PECintegrated circuits100 is or are provided (depending upon the printing speed required) in order to enable page-width printing over a variety of different sized pages or continuous sheets. As described previously, each of the printedcircuit boards63 carried by thesupport moulding66 carries one PEC integrated circuit190 (FIG. 25) which interfaces with four of the print head chips57, and the PECintegrated circuit190 essentially drives the integrated circuits of the print head chips57 and transfers received print data thereto in a form suitable to effect printing.

An example of a PEC integrated circuit which is suitable for driving the print head chips is described in the Applicant's co-pending U.S. patent application Ser. No. 09/575,108 (Docket No. PEC01US), Ser. No. 09/575,109 (Docket No. PEC02US), Ser. No. 09/575,110 (Docket No. PEC03US), Ser. No. 09/607,985 (Docket No. PEC04US), Ser. No. 09/607,990 (Docket No. PEC05US) and Ser. No. 09/606,999 (Docket No. PEC07US), which are incorporated herein by reference. However, a brief description of the circuit is provided as follows with reference to FIGS.28 to30.

The data flow and functions performed by the PECintegrated circuit190 are described for a situation where the PEC integrated circuit is provided for driving aprint head assembly50 an51 having a plurality ofprint head modules55, that is four modules as described above. As also described above, eachprint head module55 provides for six channels of fluid for printing, these being:

- Cyan, Magenta and Yellow (CMY) for regular colour printing;
- Black (K) for black text and other black or greyscale printing;
- Infrared (IR) for tag-enabled applications; and
- Fixative (F) to enable printing at high speed.

As indicated inFIG. 28, photographic images are supplied to the PECintegrated circuit190 by thecomputer20, which is programmed to perform thevarious processing steps191 to194 involved in printing an image prior to transmission to the PECintegrated circuit190. These steps will typically involve receiving the image data (step191) and storing this data in a memory buffer of the computer system (step192) in which photograph layouts may be produced and any required objects may be added. Pages from the memory buffer are rasterized (step193) and are then compressed (step194) prior to transmission to the PECintegrated circuit190. Upon receiving the image data, the PECintegrated circuit190 processes the data so as to drive the integrated circuits of the print head chips57.

Due to the page-width nature of the printhead assembly of the present invention, each photographic image should be printed at a constant speed to avoid creating visible artifacts. This means that the printing speed should be varied to match the input data rate. Document rasterization and document printing are therefore decoupled to ensure the printhead assembly has a constant supply of data. In this arrangement, an image is not printed until it is fully rasterized and, in order to achieve a high constant printing speed, a compressed version of each rasterized page image is stored in memory.

Because contone colour images are reproduced by stochastic dithering, but black text and line graphics are reproduced directly using dots, the compressed image format contains a separate foreground bi-level black layer and background contone colour layer. The black layer is composited over the contone layer after the contone layer is dithered. If required, a final layer of tags (in IR or black ink) is optionally added to the image for printout.

Dither matrix selection regions in the image description are rasterized to a contone-resolution bi-lev bitmap which is losslessly compressed to negligible size and which forms part of the compressed image. The IR layer of the printed page optionally contains encoded tags at a programmable density.

Each compressed image is transferred to the PECintegrated circuit190 where it is then stored in amemory buffer195. The compressed image is then retrieved and fed to animage expander196 in which images are retrieved. If required, any dither may be applied to any contone layer by a dithering means197 and any black bi-level layer may be composited over the contone layer by acompositor198 together with any infrared tags which may be rendered by the rendering means199. The PECintegrated circuit190 then drives the integrated circuits of the print head chips57 to print the composite image data atstep200 to produce a printed (photograph)image201.

The process performed by the PECintegrated circuit190 may be considered to consist of a number of distinct stages. The first stage has the ability to expand a JPEG-compressed contone CMYK layer. In parallel with this, bi-level IR tag data can be encoded from the compressed image. The second stage dithers the contone CMYK layer using a dither matrix selected by a dither matrix select map and, if required, composites a bi-level black layer over the resulting bi-level K layer and adds the IR layer to the image. A fixative layer is also generated at each dot position wherever there is a need in any of the C, M, Y, K, or IR channels. The last stage prints the bi-level CMYK+IR data through theprint head assembly50 and/or51.

FIG. 29 shows the PECintegrated circuit190 in the context of the overall printing system architecture. The various components of the architecture include:

- The PECintegrated circuit190 which is responsible for receiving the compressed page images for storage in amemory buffer202, performing the page expansion, black layer compositing and sending the dot data to the print head chips57. The PECintegrated circuit190 may also communicate with a master Quality Assurance (QA)integrated circuit203 and with an ink cartridge Quality Assurance (QA)integrated circuit204. The PECintegrated circuit190 also provides a means of retrieving the print head assembly characteristics to ensure optimum printing.
- Thememory buffer202 for storing the compressed image and for scratch use during the printing of a given page. The construction and working of memory buffers is known to those skilled in the art and a range of standard integrated circuits and techniques for their use might be utilized.
- The master integratedcircuit203 which is matched to the ink cartridge QA integratedcircuit204. The construction and working of QA integrated circuits is also known to those skilled in the art and a range of known QA processes might be utilized.

The PECintegrated circuit190 of the present invention effectively performs four basic levels of functionality:

- Receiving compressed pages via a serial interface such as an IEEE 1394.
- Acting as a print engine for producing an image from a compressed form. The print engine functionality includes expanding the image, dithering the contone layer, compositing the black layer over the contone layer, optionally adding infrared tags, and sending the resultant image to the integrated circuits of the print head chips.
- Acting as a print controller for controlling the print head chips57 and thestepper motors102,108 and111 of the printing system.
- Serving as two standard low-speed serial ports for communication with the two QA integrated circuits. In this regard, two ports are used, and not a single port, so as to ensure strong security during authentication procedures.

These functions are now described in more detail with reference toFIG. 30, which provides a more specific, exemplary illustration of the PEC integrated circuit architecture.

The PECintegrated circuit190 incorporates a simplemicro-controller CPU core204 to perform the following functions:

- Perform QA integrated circuit authentication protocols via aserial interface205 between print images.
- Run thestepper motors102,108 and111 of the printing system via aparallel interface206 during printing to control delivery of thepaper75 to the printer for printing.
- Synchronize the various components of the PECintegrated circuit190 during printing.
- Provide a means of interfacing with external data requests (programming registers, etc).
- Provide a means of interfacing with the print head assemblies' low-speed data requests (such as reading characterization vectors and writing pulse profiles).
- Provide a means of writing portrait and landscape tag structures to anexternal DRAM207.

In order to perform the image expansion and printing process, the PECintegrated circuit190 includes a high-speed serial interface208 (such as a standard IEEE 1394 interface), astandard JPEG decoder209, astandard Group 4Fax decoder210, a custom halftoner/compositor (HC)211, acustom tag encoder212, a line loader/formatter (LLF)213, and a print head interface214 (PHI) which communicates with the print head chips57. The

decoders

209 and210 and thetag encoder212 are buffered to theHC211. Thetag encoder212 allocates infrared tags to images.

The print engine function works in a double-buffered manner. That is, one image is loaded into theexternal DRAM207 via aDRAM interface215 and a data bus216 from the high-speedserial interface208, while the previously loaded image is read from theDRAM207 and passed through the print engine process. When the image has been printed, the image just loaded becomes the image being printed, and a new image is loaded via the high-speedserial interface208.

At the aforementioned first stage, the process expands any JPEG-compressed contone (CMYK) layers, and expands any of twoGroup 4 Fax-compressed bi-level data streams. The two streams are the black layer and a matte for selecting between dither matrices for contone dithering. At the second stage, in parallel with the first, any tags are encoded for later rendering in either IR or black ink.

Finally, in the third stage the contone layer is dithered, and position tags and the bi-level spot layer are composited over the resulting bi-level dithered layer. The data stream is ideally adjusted to create smooth transitions across overlapping segments in the print head assembly and ideally it is adjusted to compensate for dead nozzles in the print head assemblies. Up to six channels of bi-level data are produced from this stage.

However, it will be understood that not all of the six channels need be activated. For example, theprint head modules55 may provide for CMY only, with K pushed into the CMY channels and IR ignored. Alternatively, the position tags may be printed in K if IR ink is not employed. The resultant bi-level CMYK-IR dot-data is buffered and formatted for printing with the integrated circuits of the print head chips57 via a set of line buffers (not shown). The majority of these line buffers might be ideally stored on theexternal DRAM207. In the final stage, the six channels of bi-level dot data are printed via thePHI214.

TheHC211 combines the functions of half-toning the contone (typically CMYK) layer to a bi-level version of the same, and compositing the spot1 bi-level layer over the appropriate half-toned contone layer(s). If there is no K ink, theHC211 functions to map K to CMY dots as appropriate. It also selects between two dither matrices on a pixel-by-pixel basis, based on the corresponding value in the dither matrix select map. The input to theHC211 is an expanded contone layer (from the JPEG decoder205) through abuffer217, an expanded bi-level spot1 layer through abuffer218, an expanded dither-matrix-select bitmap at typically the same resolution as the contone layer through abuffer219, and tag data at full dot resolution through a buffer (FIFO)220.

TheHC211 uses up to two dither matrices, read from theexternal DRAM207. The output from theHC211 to theLLF213 is a set of printer resolution bi-level image lines in up to six colour planes. Typically, the contone layer is CMYK or CMY, and the bi-level spot1 layer is K. Once started, theHC211 proceeds until it detects an “end-of-image” condition, or until it is explicitly stopped via a control register (not shown).

TheLLF213 receives dot information from theHC211, loads the dots for a given print line into appropriate buffer storage (some on integrated circuit (not shown) and some in the external DRAM207) and formats them into the order required for the integrated circuits of the print head chips57. More specifically, the input to theLLF213 is a set of six 32-bit words and a Data Valid bit, all generated by theHC211.

As previously described, the physical location of thenozzles150 on the print head chips is in two offset rows151, which means that odd and even dots of the same colour are for two different lines. In addition, there is a number of lines between the dots of one colour and the dots of another. Since the six colour planes for the same dot position are calculated at one time by theHC211, there is a need to delay the dot data for each of the colour planes until the same dot is positioned under the appropriate colour nozzle. The size of each buffer line depends on the width of the print head assembly. A single PECintegrated circuit190 may be employed to generate dots for up to 16 print head chips57 and, in such case, a single odd or even buffer line is therefore16 sets of 640 dots, for a total of 10,240 bits (1280 bytes).

ThePHI214 is the means by which the PECintegrated circuit190 loads the print head chips57 with the dots to be printed, and controls the actual dot printing process. It takes input from theLLF213 and outputs data to the print head chips57. ThePHI214 is capable of dealing with a variety of print head assembly lengths and formats.

A combined characterization vector of each

print head assembly

50 and51 can be read back via theserial interface205. The characterization vector may include dead nozzle information as well as relative printhead module alignment data. Each printhead module can be queried via a low-speedserial bus221 to return a characterization vector of the printhead module.

The characterization vectors from multiple printhead modules can be combined to construct a nozzle defect list for the entire printhead assembly and allows the PECintegrated circuit190 to compensate for defective nozzles during printing. As long as the number of defective nozzles is low, the compensation can produce results indistinguishable from those of a printhead assembly with no defective nozzles.

It will be understood that the broad constructional and operating principles of the photofinishing system of the present invention may be realised with various embodiments. Thus, variations and modifications may be made in respect of the embodiments as specifically described above by way of example.